Double gripper cylinder



Jan; 6, 1942. L. BISCHOFF ET AL DOUBLE GRIPPER CYLINDER Filed April 20, 1938 2 Sheets-Sheet l v nm- T 4 89' 45014118 fup dzmrd 372a 1942' L. BISCHOFF ET AL 2,268,921

DOUBLE GRIPPER CYLINDER Filed April 20, 1938 2 Sheets-Sheet 2 INVENT R. QGouLs $31.8 hoff' ATTORNEY-5 Patented Jan. 6, 1942 ILouis Bischofi, Rupert Loefiler, Jr, and Edward T.Jaeger, New York, N. Y.,.assig'nors.to. Oneida pora'tionof New York Paper Products; Inc., 'NewLYorlgY, acor- Application April 20, 193:8, Seria1 No.i203;030 LCla-im. (ores-98 Our invention relates to a drum-: forholding creased bag bottoms during the bottom forming operation in-bag making, and more specifically relates to a drum having double gripper mechanisms whereby, upon a bag bottom being-creased into aslot in the drum of our apparatus, gripper arms move to hold such folded bag bottoms so that the creased bottoms can be properly folded in the formation of the :bag bottom. v Heretofore in the formation of bag bottoms it has been customary to use a creaser blade to stuff aportion of the bagv bottom into a groove which may be, for example,- rubber lined. There is a certain retention for thestuffed-in paper, but such mechanisms have been found to be lacking in the desired certainty of action which is-necessary in the high speed and entirely automatic machine operations which are attendant upon the present day formation of bags. Thus, it has been found that, oftentimes, the creased or stuffed-in paper forced into the groove in the drum would have a tendency to escape from. the groove, which, of course, would throw, off completely the bottom forming operation and resu in rejects. 1

We have conceived and developed: a novel apparatus for surely and certainly maintaining .the necessarycreased portions of the bag-bottom in proper position during the formation of the bag bottom, Thus, we have provided a drum with two sets of grooves. In the grooves,.mechanisms are positioned whichreceive the 'bag. bottom portions stuffed therein by creaser'blades ahdproceed to firmly grip these creased portions to properly position and hold the creased portions 'during the bottom forming operation. Thus, as the folded paper passes over the drum. and the creaser blades crease the proper portions of the paper into the grooves in the drum, synchronized gripper armslocated in the grooves move so as to press firmly the creased-in paper and maintain it in that position until supplemental mechanisms have acted to fold over the ends of the creased paper to form the bag bottom. Thereupon the creaser arms move so as to release the creased-in paper and permit the bag to move on.

It is an object of our invention to provide a novel bag bottom gripper cylinder.

It is a further object of our invention to provide a novel cylinder having sets of multiple grooves wherein the creased portions of the bag bottom are firmly held during the bottom forming operation.

It is a further object of our invention to progripper "mechanisms which synchronously operate to; hold the creased portion ''0f the bag :bottom during the bottom forming operation.

lt'jiscafurther object of our invention to provide .a .drumtwhich moves about a stationary cam so that in timed operation, gripper arms; located w ithinithe gripperslots-10f the drum act to press and holdifirmlycreased paper'sections. I Y

Other objects will be apparent .upon :the description of the: apparatus which will :be set forth together, with theyfollowing drawings: l In Figure 1 is shown an end view of the double gripper mechanism of-our invention in combination with the creaser. s -Figure2 is a cross-section and partial elevation taken along the line 12-52 of Figure 1 looking :in the :;direction of :the arrows.

Figure 3 ris-a'view-taken along the line-33 of Figure 2 showing the "double gripper appara g the line 5-5 of ings, we have shown in Figure 1- the folded Paper i which travels along in the direction indicated by the arrow. -The paper has been previously-folded to tubular form. The forwardend of the.- folded papenhas beenspread. by suitable spreading'mechanisminto a" diamond shape .at its advancing end. As the advancing folded paper passes between the suitably mountedcreaser blades I0 and the double gripper cylinder II, the creaser blades. I!) force the paper I into the grooves 12 and I3. As the drum moves and the creaser blades H] are withdrawn from the grooves, the gripper arms [5 and I6 move against the creased paper to hold it in its proper position in the grooves. The gripper arms I5 and I6 move about the fixed pivots l1 and I8. The structure and power source of the gripper arm IE will be specifically described since the multiplicity of gripper arms are actuated in a similar manner. Thus the gripper arm 5 is pivoted about the shaft l8. The movement of the gripper arm I6 is governed by the roller 20 mounted on the arm 2| by means of the pin 22. The roller20 rides vide a double gripper cylinder wherein are located upon the cam surface 25 which has a high Sui" crease in the paper which is to form the bag.

bottoms, as they are carried on the drum in a predetermined path.

The construction of the apparatus will now b set forth. The drum 50 has openings 5| with suitable surfaces 53 and 54 in which are set blocks 36 and 36'. The blocks are secured to the drum 50 by means of bolts 38 which are set in tapped holes 55 in the drum 50. In this block 36 is a groove I3 in which is set the gripper arm IS. The gripper arm, as shown in Figure 4, comprises a gripper surface 60 terminating in an extension 6I. This extending surface of'the gripper arm is engaged between the split members 62 and B3 of the arm 2 I. A bolt 64 tightens these split members together so that the arm 2| is rigidly fixed with respect to this integral shaft extension of the gripper arm I6. Adjacent to the grippers I6 and coacting therewith are the grippers I5 which are located in the block 35 mounted on the spoke III which terminates in a hub rotating with the drum 5!) about the shaft 4|.

As shown in Figure 3, in order to secure varying bottom widths, as is necessary in different bags, adjustment is made possible between the block 35 and the block 36, to provide proper spacing therebetween, by moving the spoke 1|! away from the block 35. This is made possible by means of the slotted members I5 and bolts I6. Washers secure engagement between the slotted members 15 and bolts I6. Thus when it is desired to vary the distance between the block 35 and block 36, the bolts 16 are loosened, and spoke I is moved so as to bring the block 35 closer to the block 36. When the proper position has been reached, the bolts I6 are tightened, and the spoke 10 is rigidly fixed with respect to the drum 50. The actuating arms for the gripper I6 located in the drum 50 are positioned in the foreground of the side elevation of Figure 1. The actuating arms of the gripper I located in the spoke are located in the rear of the side elevation shown in Figure 1.

The gripper arm I5 and its actuation are more clearly shown in Figure 2, where can'be seen the gripper arm I5 which extends into, and is integral with, a shaft 80 gripped by a split member 8| which forms one end of an arm 82 carrying a roller 83 riding on the cam 84. The spring 85 fixed to the frame by the pin 86 presses the roller 83 down onto the cam 84. The cam 84 is mounted on bearing 81 which extends into the frame 90 where it is fixed. In Figure 2, the split member 62 which grips the pivot I8 is shown. The gripper I5 terminates at the point 88.

The corresponding gripper arms I5 and I 6 and their actuated mechanisms are identified by the same numbers as gripper arms I5 and I 6. It is to be understood that this double gripper cylinder has for speed of operation two sets of set holding the creases in a single section of paper to form the bag bottom therein.

This double gripper mechanism of our invention provides a sure and accurate way of maintaining the gripped bag bottoms in proper position during the bottom forming operations. It is a radical improvement over the prior rubber groove which merely engaged, by frictional engagement, the creased bottoms. By means of the stationary cam and the arm actuated gripper which rotates with the drum, a synchronized gripping action is obtained. The adjustment of distances between the respective gripper arms is easily fixed as shown above. It has been found that the gripper mechanism herein provided makes possible elimination of inaccurate operation and slippage hitherto common in this art. It is a distinct step in removing, in bag making machines, the possibilities of malformation that have been so common.

Although we have set forth a specific mechanism for employing this positive gripping action, it is to be understood that we do not limit ourselves to the particular mechanisms which have been set forth by way of example, but we intend to cover broadly mechanisms that accomplish these results as set forth in the appended claim.

We claim:

A gripper cylinder comprising a drum, a groove in said drum, a gripper arm in said groove, said gripper arm being mounted to rotate on a shaft to move against a wall of the groove, said gripper arm being actuated by a second arm, said second arm carrying a roller, said roller being actuated by a cam, said gripper arm being impelled against the wall of said groove by means of a spring, said spring being mounted at the end of said second arm, an extension mounted on said second arm for moving said gripper arm away from said wall.

LOUIS BISCHOFF. RUPERT LOEFFLER, JR. EDWARD T. JAEGER. 

